Light emitting apparatus and light radiator including the same

ABSTRACT

A light emitting apparatus includes a substrate, a plurality of light emitting structures, a window, and a reflector. The substrate has a luminous region and a non-luminous region. The plurality of light emitting structures is disposed on the luminous region of the substrate. The window has a dome shape and is disposed to cover the luminous region. The window is configured to control a traveling path of light emitted from the a plurality of light emitting structures. The reflector is configured to support the window and reflect the light emitted from the plurality of light emitting structures. The reflector has an opening that exposes the plurality of light emitting structures mounted on the substrate. A distance between two adjacent light emitting structures of the plurality of light emitting structures is 500 micrometers or less.

CROSS-REFERENCE OF RELATED APPLICATIONS AND PRIORITY

The Present Application is a continuation of U.S. patent applicationSer. No. 17/170,350 filed Feb. 8, 2021 which is a continuation ofInternational Application No. PCT/KR/2019/009763 filed Aug. 6, 2019which claims priority to Korean Application No. 10-2018-0091142 filedAug. 6, 2018, the disclosures of which are incorporated by reference intheir entirety as if they are fully set forth herein.

TECHNICAL FIELD

Embodiments of the present disclosure relate to a light emittingapparatus and a light radiator including the same.

BACKGROUND

A light emitting diode refers to a semiconductor device that emits lightthrough recombination of electrons and holes. The light emitting diodeemits light in various wavelength bands, such as visible light and UVlight, and may be used as a UV curing machine, a sterilizer, a lightsource, and the like. In particular, UV light emitting diodes are widelyused in UV curing devices.

SUMMARY

Embodiments of the present disclosure provide a light emitting apparatusemitting uniform light and a light radiator including the same.

According to one or more embodiments of the present disclosure, a lightemitting device includes a substrate having a luminous region and anon-luminous region, a plurality of light emitting structures disposedon the luminous region of the substrate, a window, a reflector, and anadhesive layer. The window has a dome shape and is disposed to cover theluminous region. The window is configured to control a traveling path oflight emitted from the a plurality of light emitting structures. Thereflector is configured to support the window and reflect the lightemitted from the plurality of light emitting structures. The reflectorhas an opening that exposes the plurality of light emitting structuresmounted on the substrate. The adhesive layer is disposed between thewindow and the reflector. The window includes a base and a lens formedabove one of surfaces of the base and an end portion of the baseprotrudes from a side surface of the lens. The window is configured tohave a convex shape in the light traveling direction. A distance betweentwo adjacent light emitting structures of the plurality of lightemitting structures is 500 micrometers or less.

In at least one variant, the non-luminous region is provided withconductive patterns electrically connected to the plurality of lightemitting structures.

In another variant, the plurality of light emitting structures emitlight, via the dome shape of the window, at a beam angle of 90 degreesof more.

In another variant, in a light profile of light emitted from the lightemitting device, a difference between a valley value and a peak value is10% or less.

In another variant, the opening defines the luminous region and the lenshas a bottom shape corresponding a shape of the opening.

In another variant, a height of the window is 70% or less of a lowerdiameter thereof.

In another variant, the distance between the two adjacent light emittingstructures of the plurality of light emitting structures is 200micrometers.

In another variant, the luminous region includes a first pad disposedbetween the substrate and each of the light emitting structures, and asecond pad disposed around the luminous region, wherein the plurality oflight emitting diodes are connected to the second pad by electricalbonding.

In another variant, the light emitting structures emit UV light.

According to one or more embodiments of the present disclosure, a lightemitting device includes a substrate having a first region and a secondregion, a plurality of light emitting structures disposed on the firstregion of the substrate, a window, and a reflector. The window has adome shape and is disposed to cover the first region. The window isconfigured to control a traveling path of light emitted from theplurality of light emitting structures. The reflector is configured tosupport the window and reflect the light emitted from the plurality oflight emitting structures. The reflector has an opening that exposes theplurality of light emitting structures mounted on the substrate. Thewindow includes a base and a lens formed on one surface of surfaces ofthe base. The window is configured to have a convex shape in the lighttraveling direction. An end portion of the base protrudes from a sidesurface of the lens. In a profile of light emitted from the lightemitting device, a difference between a valley value and a peak value is10% or less.

In at least one variant, a distance between two adjacent light emittingstructures is 500 micrometers or less.

In another variant, the second region is provided with conductivepatterns electrically connected to the light emitting structures.

In another variant, the plurality of light emitting structures emitlight, via the dome shape of the window, at a beam angle of 90 degreesof more.

In another variant, the opening defines the first region and the lensportion has a bottom shape corresponding a shape of the opening.

According to one or more embodiments of the present disclosure, a lightemitting device includes a substrate having a luminous region and anon-luminous region, a light emitting unit disposed on the luminousregion of the substrate, a window disposed to cover the luminous region,the window configured to control a traveling path of light emitted fromthe light emitting unit, a reflector configured to support the windowand reflect the light emitted from the light emitting unit, and anadhesive layer. The reflector has an opening that exposes the lightemitting unit mounted on the substrate. The adhesive layer is disposedbetween the substrate and the reflector. The window includes a base anda lens formed on one surface of surfaces of the base and is configuredto have a convex shape in the light traveling direction. A height of thelens is 70% or less of a lower diameter thereof. In a light profile oflight emitted from the light emitting device, a difference between avalley value and a peak value is 10% or less.

In at least one variant, the non-luminous region is provided withconductive patterns electrically connected to the light emitting unit.

In another variant, the light emitting device further includes aphosphor portion disposed in the window.

In another variant, the reflector has a stepped portion on a top surfacethereof.

In another variant, the lens has a larger area than a size of theopening.

In another variant, an inner wall of the opening has an inclinedportion.

In accordance with one embodiment of the present disclosure, a lightemitting apparatus including a substrate, a plurality of light emittingdiodes arranged in a matrix on the substrate, and a window disposed in adome shape on the light emitting diodes and controlling a traveling pathof light emitted from the light emitting diodes. A height of the windowis 70% or less of a lower diameter thereof such that the light emittedfrom the light emitting diodes is condensed at a beam angle of 90degrees or less.

In at least one variant, the window may include a base and a lensportion protruding from one surface of the base and having a circularshape in plan view, and the lens portion may have different gradientvariations depending upon an angle from an upper surface of the basewith reference to the center of the circular shape on a cross-section ofthe lens portion perpendicular to the upper surface of the base andtaken across the center of the circular shape on the base.

In another variant, assuming that the lens portion sequentially hasfirst to m^(th) regions (m being an integer of 3 or more) according toan angle from the upper surface of the base with reference to the centerof the circular shape, a gradient variation in an n^(th) region (1<n<m)may be greater than a gradient variation in an (n−1)^(th) region and agradient variation in an (n+1)^(th) region.

In yet another variant, on a cross-section of the lens portion takenacross the center thereof, a curve constituting the lens portion mayhave a radius of curvature gradually decreasing and then increasing in adirection from the upper surface of the base towards a vertex of thelens portion.

In further another variant, assuming that radii of curvature at threepoints sequentially disposed on a cross-section of the lens portiontaken across the center thereof are referred to as first to third radiiof curvature, respectively, the second radius of curvature may be lessthan the first and third radii of curvature.

In further another variant, the light emitting diodes may be disposed ona surface of the substrate corresponding to a region between pointshaving the smallest radius of curvature at opposite sides on across-section of the lens portion taken across the center thereof.

In another variant, the light emitting diodes may emit light at a beamangle of 90 degrees or more.

In another variant, a distance between two adjacent light emittingdiodes may be 500 micrometers or less.

In another variant, each of the light emitting diodes may beindependently driven and may be a vertical type.

In another variant, in a profile of light emitted from the lightemitting apparatus, a difference between a valley value and a peak valuemay be 10% or less.

In another variant, the light emitting apparatus may further include: afirst pad disposed between the substrate and each of the light emittingdiodes and a second pad disposed around the luminous region, wherein thelight emitting diodes may be connected to the second pad by wirebonding.

In another variant, the light emitting diodes may emit UV light.

In some forms, the light emitting apparatus according to the embodimentsof the present disclosure may be employed by a light radiator. The lightradiator may include a plurality of light emitting apparatuses, whereineach of the light emitting apparatuses may include a substrate, aplurality of light emitting diodes arranged in a matrix on thesubstrate, and a window disposed in a dome shape on the light emittingdiodes and controlling a traveling path of light emitted from the lightemitting diodes. A height of the window is 70% or less of a lowerdiameter thereof such that the light emitted from the light emittingdiodes is condensed at a beam angle of 90 degrees or less thereby.

Embodiments of the present disclosure provide a light emitting apparatushaving high reliability. Embodiments of the present disclosure provide alight radiator employing the light emitting apparatus to emit uniformlight.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a light emitting apparatus according toone embodiment of the present disclosure.

FIG. 2 is an exploded perspective view of the light emitting apparatusshown in FIG. 1 .

FIG. 3 is a plan view of the light emitting apparatus shown in FIG. 1 .

FIG. 4 is a cross-sectional view taken along line I-I′ of FIG. 3 .

FIG. 5 is a sectional view of a light emitting diode according to oneembodiment of the present disclosure.

FIG. 6A is a perspective view of a window in the light emittingapparatus according to the embodiment of the present disclosure, and

FIG. 6B is a cross-sectional view of the window taken along line II-II′of FIG. 6A.

FIG. 6C is a cross-sectional view of the window taken along line II-II′of FIG. 6A.

FIG. 7A is a view of a conventional window of a conventional lightemitting apparatus.

FIG. 7B is a view of a light profile of a conventional light emittingapparatus.

FIG. 8A is a view of a window according to one embodiment of the presentdisclosure

FIG. 8B is a light profile of a light emitting apparatus including thewindow of FIG. 8A.

FIG. 9A is a simulation profile of light emitted from a conventionallight emitting apparatus including a window.

FIG. 9B is a simulation profile of light emitted from anotherconventional light emitting apparatus.

FIG. 9C is a simulation profile of light emitted from further anotherconventional light emitting apparatus.

FIG. 10A is a simulation profiles of light emitted from a light emittingapparatus including a window according to one embodiment of the presentdisclosure.

FIG. 10B is a simulation profile of light emitted from another lightemitting apparatus.

FIG. 10C is a simulation profile of light emitted from further anotherlight emitting apparatus.

FIG. 11A is a light profile of light emitting apparatus including awindow having a similar shape to the window shown in FIG. 8A and adifferent height from the window shown in FIG. 8A.

FIG. 11B is a light profile of light emitting apparatus including awindow having a different height from the window shown in FIG. 11A.

FIG. 11C is a light profile of light emitting apparatus including awindow having a different height from the window shown in FIG. 11B.

FIG. 12 is a perspective view of a light emitting apparatus according toone embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

It should be understood that various modifications, variations, andalterations can be made by those skilled in the art without departingfrom the spirit and scope of the present disclosure and specificembodiments will be illustrated in the drawings and described in detail.However, it should be understood that these embodiments are given by wayof example only and are not intended to limit the present disclosure.Therefore, the scope of the present disclosure should be defined by theappended claims and equivalents thereto.

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail.

FIG. 1 is a perspective view of a light emitting apparatus according toone embodiment and FIG. 2 is an exploded perspective view of the lightemitting apparatus shown in FIG. 1 . FIG. 3 is a plan view of the lightemitting apparatus shown in FIG. 1 and FIG. 4 is a cross-sectional viewtaken along line I-I′ of FIG. 3 .

Referring to FIG. 1 to FIG. 4 , the light emitting apparatus accordingto the embodiment of the present disclosure includes a substrate 110defining an overall shape of the light emitting apparatus, a pluralityof light emitting diodes 120 disposed on the substrate 110 and emittinglight, and a window 190 disposed on the light emitting diodes 120 tocontrol a traveling path of the light emitted from the light emittingdiodes 120.

A pad portion is provided to the light emitting diodes 120 andelectrically connected thereto. The pad portion may be connected to aterminal unit for electrical connection to external elements. The lightemitting apparatus may be further provided with additional elementsincluding the window allowing transmission of light emitted from thelight emitting diodes 120 therethrough, an antistatic element 160, andthe like.

The substrate 110 is configured to have at least one light emittingdiode 120 mounted thereon.

The substrate 110 may be provided with the at least one light emittingdiode 120 and interconnects, for example, the pad portion, the terminalunit and/or connectors, to connect the at least one light emitting diode120 to an external power source, external wires, and the like.

The substrate 110 may have various shapes. By way of example, thesubstrate 110 has a substantially square shape in plan view and may berealized by a plate having a certain height. Alternatively, thesubstrate 110 may be provided in a rectangular shape in plan view andmay have a pair of long sides and a pair of short sides. However, itshould be understood that the shape or size of the substrate 110 is notlimited thereto.

At least part of the substrate 110 may be formed of a conductivematerial. The substrate 110 may be formed of, for example, a metal,which may include copper, iron, nickel, chromium, aluminum, silver,gold, titanium, and alloys thereof. However, it should be understoodthat the substrate 110 is not limited thereto and may be formed of anon-conductive material. For the substrate 110 formed of thenon-conductive material, a conductor may be disposed on an upper surfaceof the substrate 110. The non-conductive material may include a ceramicmaterial, a resin, glass, or a composite thereof (for example, acomposite resin or a mixture of a composite resin and a conductivematerial).

An insulating layer may be further disposed on the substrate 110 andfirst and second pads 111, 130 described below may be provided on theinsulating layer.

The substrate 110 has a luminous region in which the light emittingdiodes 120 are disposed to emit light and a non-luminous regionexcluding the luminous region. The luminous region and the non-luminousregion may be determined according to the presence and arrangement ofthe light emitting diodes 120, and the non-luminous region is providedwith conductive patterns (for example, the pad portion, the terminalunit, and the like) electrically connected to the light emitting diodes120 and with various elements (for example, the antistatic element 160,a temperature measurement device 170, and the like).

The luminous region is provided with the plurality of light emittingdiodes 120, which will be described below.

The substrate 110 may have a monolithic structure, without being limitedthereto. Alternatively, the substrate 110 may be realized by acombination of two sub-substrates 110.

The substrate 110 may be provided with a reflector 180 having a steppedportion 181 on which the window 190 is mounted. The window 190 may bemounted on the stepped portion 181 of the reflector 180. The steppedportion 181 may have a depth substantially the same as a thickness of abase 191 of the window 190, whereby an upper surface of the base 191 maybe coplanar with an upper surface of the reflector 180 excluding thestepped portion 181. Alternatively, the stepped portion 181 may have agreater thickness than the window 190.

The window 190 may be disposed in the luminous region of the substrate110. That is, the window 190 is disposed in a region in which the lightemitting diodes 120 are arranged and through which light emitted fromthe light emitting diodes 120 travels. That is, the window 190 may havean area corresponding to the luminous region or a larger area than theluminous region. With this structure, the window 190 may cover theentirety of the luminous region.

In this embodiment, the window 190 may have a lens shape that condenseslight. The window 190 may include a plate-shaped base 191 and a lensportion 193 protruding upwards from the base 191, as shown in FIGS. 1and 2 .

In some forms, the window 190 is formed of a transparent insulatingmaterial to transmit light emitted from the light emitting diodes 120and protects the light emitting diodes 120 while transmitting the lightemitted from the light emitting diodes 120. Further, the window 190 actsas an optical lens and changes a traveling path of light so as to have apredetermined beam angle upon transmission of light therethrough. Forexample, the lens portion 193 condenses light emitted from the lightemitting diodes 120 so as to emit light at a beam angle of 90 degrees orless. According to the embodiment, even when the light emitting diodes120 emit light at a beam angle of 90 degrees or more, the window 190condenses the light emitted from the light emitting diodes 120 so as toemit light at a beam angle of 90 degrees or less. As a result, theemitted light has a relatively uniform profile.

The window 190 may be formed of a material that is not deformed ordiscolored by light emitted from the light emitting diodes 120. Forexample, when the light emitted from the light emitting diodes 120 is UVlight, the window 190 may be formed of a material that is not deformedor discolored by UV light. The window 190 may be formed of variousmaterials so long as the window can have the functions described abovewithout being limited to a particular material. For example, the window190 may be formed of quartz or a polymer organic material. Here, sincepolymer glass materials have different absorption/transmissionwavelengths depending on the type of monomer, a molding method andmolding conditions, the polymer glass material may be selected inconsideration of the wavelength of light emitted from the light emittingdiodes 120. For example, organic polymers, such as poly(methylmethacrylate) (PMMA), polyvinyl alcohol (PVA), polypropylene (PP), andlow-density polyethylene (PE), hardly absorb UV light, whereas organicpolymers such as polyesters can absorb UV light.

In one embodiment, the base 191 (FIG. 2 ) may have a substantiallysquare shape and the lens portion 193 may have a circular shape in planview. However, these shapes are provided by way of example and the base191 may have a different shape in plan view and, for example, may havethe same shape as the lens portion 193. In particular, the shape of thebase 191 may be changed according to the shape of an opening 183 of thereflector 180, which will be described below. When the opening 183 has acircular shape, the base 191 may also have a circular shape similar tothe lens portion 193.

The shape of the window 190 will be further described below.

The reflector 180 supports the window 190 while reflecting the lightemitted from the light emitting diodes 120. In particular, a sidewall ofthe reflector 180 facing the light emitting diodes 120 reflects thelight emitted from the light emitting diodes 120.

The reflector 180 is coupled to an upper portion of the substrate 110.The reflector 180 may be formed with the opening 183 that exposes thelight emitting diodes 120 mounted on the substrate 110. The opening 183may have a rectangular shape in plan view, but it is not limitedthereto. Alternatively, the opening 183 may have a circular shape orother polygonal shapes. Such a shape may be modified in various waysdepending upon a mounting structure of the light emitting diodes 120 ora desired shape of light emitted from the light emitting apparatus.

The window 190 may be mounted on a portion of the reflector 180 in whichthe opening 183 is formed. To this end, a stepped portion, for example,a mounting groove, may be formed on an inner surface of the opening 183.

Further, the reflector 180 may be provided with a fastening portion 150for fastening with the substrate 110, as shown in FIGS. 1 and 3 . Thefastening portion 150 may be realized in various forms, for example, inthe form of at least one fastening hole 151, which is formed throughupper and lower surfaces of the reflector, and a screw 153 inserted intothe fastening hole 151, as shown in FIG. 2 . The fastening hole 151 maybe provided to each of opposite sides of the reflector 180. Although notshown, the substrate 110 may be provided with substrate holescorresponding to the fastening holes 151, in which the substrate holesmay have substantially the same diameter as that of the fastening holes.The reflector 180 may be fastened to the substrate 110 using fasteningmembers, such as screws 153, with the fastening holes 151 and thesubstrate holes disposed at the same locations.

In this embodiment, the reflector 180 serves to guide light emitted fromthe light emitting diodes 120 disposed inside the opening 183 to bedischarged through an upper portion thereof while protecting the lightemitting diodes 120 disposed inside the opening 183.

Further, the reflector 180 may include a metal such that heat generatedfrom the light emitting diodes 120 can be transferred to the reflector180 through the substrate 110 so as to be dissipated through thereflector 180.

A coating may be formed on an outer surface of the reflector 180 by ananodizing method, whereby the outer surface of the reflector 180 may beblack.

The window 190 is inserted into the stepped portion 181 formed on thereflector 180 to be coupled to the reflector 180. Accordingly, thewindow 190 may have a larger area than the opening. In addition, thewindow 190 may be formed of a material, such as glass and the like, andmay have one or more types of phosphors dispersed therein.

The reflector 180 may be bonded to the substrate 110 via a bonding layer107 interposed therebetween, as shown in FIG. 4 . The bonding layer 107may be formed of any material capable of bonding the reflector 180 tothe substrate 110 without being limited to a particular material.

The bonding layer 107 may be formed of an organic polymer-containingorganic adhesive or a metal-containing solder. When the bonding layer107 is formed of the organic adhesive, the bonding layer 107 may beinterposed between the reflector 180 and the substrate 110 to bond thereflector 180 to the substrate 110. When the bonding layer 107 is formedof the metal-containing solder, the bonding layer 107 may be subjectedto surface treatment such that opposite surfaces of the reflector 180and the substrate 110 facing each other can be soldered. For example, aseparate soldering pad may be further formed through surface treatmentto facilitate soldering in a region of the substrate 110 on which thereflector 180 will be disposed.

In this embodiment, the reflector 180 serves to guide light emitted fromthe light emitting diodes 120 disposed inside the opening 181 to bedischarged through the upper portion thereof while protecting the lightemitting diodes 120 disposed inside the opening 181. Further, thereflector 180 may include a metal such that heat generated from thelight emitting diodes 120 can be transferred to the reflector 180through the substrate 110 so as to be dissipated through the reflector180.

In this embodiment, although an inner wall of the reflector 180 definingthe opening 183 corresponding to the luminous region is illustrated asbeing perpendicular to an upper surface of the substrate 110, it shouldbe understood that other implementations are possible and the reflectormay have other shapes so as to improve luminous efficacy. For example,the inner wall of the reflector 180 defining the opening may be slantedwith respect to the upper surface of the substrate 110.

The reflector 180 may be formed with a protective groove recessed fromone side thereof towards the opening 183. That is, the protective groovemay be formed between opposite protruding ends of an outer side surfaceof the reflector 180. When the reflector 180 is disposed on thesubstrate 110, the elements (for example, the antistatic element 160,the temperature measurement device 170, and the like) mounted on thesubstrate 110 are disposed in the protective groove of the reflector 180such that the reflector 180 surrounds at least part of the elements toprotect the surrounded elements from the outside.

In some forms, the light emitting diodes 120 are provided in plural andare disposed in the luminous region of the substrate 110.

In the embodiment, the light emitting diodes 120 are arranged in amatrix. The matrix may have any shape as long as the light emittingdiodes are arranged in rows and columns as a whole, and the rows and thecolumns are necessarily be provided in the form of straight columns.

In some forms, the light emitting diodes 120 disposed between twoadjacent rows and between two adjacent columns are separated by apredetermined distance or less from each other. For example, a distanceL between two adjacent light emitting diodes 120 may be 500 micrometersor less. If the distance L between two adjacent light emitting diodes120 exceeds 500 micrometers, non-uniform illumination occurs due todifference in luminous quantity between a region above the lightemitting diodes 120 and a region above a gap between the light emittingdiodes 120. In this case, it is difficult to overcome non-uniformityeven when the window 190 condenses the light emitted from the lightemitting diodes.

In one embodiment, the light emitting diodes 120 may be connected to onepower source so as to be operated at the same time or may be connectedto different power sources so as to be independently operated.

In one embodiment, the light emitting diodes 120 may be vertical typelight emitting diodes. FIG. 5 is a sectional view of the light emittingdiode 120 according to one embodiment of the present disclosure.

Referring to FIG. 5 , the light emitting diode 120 includes a lightemitting structure, which includes a first semiconductor layer 123, anactive layer 125, and a second semiconductor layer 127, and an anode 121and a cathode 129 connected to the light emitting structure.

The first semiconductor layer 123 is doped with a first conductivitytype dopant. The first conductivity type dopant may be a p-type dopant.For instance, the first conductivity type dopant may include Mg, Zn, Ca,Sr, Ba, and the like.

In other forms, the first semiconductor layer 123 may include a nitridesemiconductor material. For example, the first semiconductor layer 123may be formed of a semiconductor material having a compositionrepresented by In_(x)Al_(y)Ga_(1-x-y)N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). In someembodiments, the semiconductor material having this composition mayinclude GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like. Thefirst semiconductor layer 123 may be formed by growing the semiconductormaterial so as to contain the p-type dopant, such as Mg, Zn, Ca, Sr, Ba,and the like.

The active layer 125 is formed on the first semiconductor layer 123 andacts as a light emitting layer. The active layer 125 is a layer in whichelectrons (holes) injected through the first semiconductor layer 123recombine with holes (electrons) injected through the secondsemiconductor layer 127 to emit light based on a band gap between energybands of materials forming the active layer 125. The active layer 125may emit light such as UV light, visible light, and IR light.

The active layer 125 may be realized by a compound semiconductor. By wayof example, the active layer 125 may be realized by at least oneselected from among Group III-V or II-VI compound semiconductors. Theactive layer 125 may employ a quantum well structure. In some forms, theactive layer 125 may have a multi-quantum well structure in whichquantum well layers and barrier layers are alternately stacked one aboveanother. However, the active layer 125 is not limited thereto and mayhave a quantum wire structure, a quantum dot structure, or the like.

The second semiconductor layer 127 is formed on the active layer 125.The second semiconductor layer 127 is a semiconductor layer doped with asecond conductivity type dopant having an opposite polarity to the firstconductivity type dopant. The second conductivity type dopant may be ann-type dopant and may include, for example, Si, Ge, Se, Te, O, C, andthe like.

In one embodiment, the second semiconductor layer 127 may include anitride semiconductor material. For example, the second semiconductorlayer 127 may be formed of a semiconductor material having a compositionrepresented by In_(x)Al_(y)Ga_(1-x-y)N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). In someembodiments, the semiconductor material having this composition mayinclude GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like. Thesecond semiconductor layer 127 may be formed by growing thesemiconductor material so as to contain the n-type dopant, such as Si,Ge, Se, Te, O, C, and the like.

The anode 121 may be disposed on a lower surface of the firstsemiconductor layer 123 to contact the first semiconductor layer 123. Inone embodiment, the anode 121 may be used as the substrate 110 providinga stack structure. The cathode 129 may be disposed on an upper surfaceof the second semiconductor layer 127 to contact the secondsemiconductor layer 127.

In one embodiment, the anode 121 and the cathode 129 may be formed ofvarious metals, for example, Al, Ti, Cr, Ni, Au, Ag, Ti, Sn, Ni, Cr, W,and Cu, or alloys thereof. The anode 121 and the cathode 129 may beformed in a single layer or multiple layers.

In one embodiment, the light emitting diode 120 may emit light invarious wavelength bands depending upon the material and stack structurethereof. The light emitted from the light emitting diode 120 isultraviolet (UV) light, visible light, or infrared (IR) light, withoutbeing limited thereto. The light emitting diodes 120 may emit lighthaving various wavelengths depending upon the material and compositionof the light emitting layer. In this embodiment, the light emittingdiode 120 may emit light in the UV wavelength band.

Although the light emitting diode 120 according to this embodiment is avertical type, it should be understood that the light emitting diode 120is not limited thereto and may be implemented with other types withoutdeparting from the concept of the present disclosure.

Referring again to FIG. 1 to FIG. 4 , the luminous region and thenon-luminous region adjacent to the luminous region are provided withthe pad portion to supply power to the light emitting diode 120.

The pad portion includes first pads 111 connected to the anodes 121 ofthe light emitting diodes 120 and second pads 130 (shown in FIG. 4 )connected to the cathodes 129 of the light emitting diodes 120.

The first pads 111 may be disposed in the luminous region and correspondto the light emitting diodes 120, respectively, and may be placed at thesame locations of the light emitting diodes 120. That is, the number offirst pads 111 may be the same as the number of light emitting diodes120 mounted on the substrate 110.

Each of the first pads 111 is provided as a site for mounting the lightemitting diode 120 and may have substantially the same shape as thelight emitting diode 120 in plan view. In the embodiment, the first pad111 may be integrally formed with the substrate 110. In this embodiment,nine light emitting diodes 120 may be disposed in the form of a 3×3matrix and nine first pads 111 may also be provided corresponding to thelight emitting diodes 120. The plurality of first pads 111 may beregularly arranged in rows and columns corresponding to arrangement ofthe light emitting diodes 120. However, it should be understood that thenumber of light emitting diodes 120 is not limited thereto.

The light emitting diode 120 is mounted on the first pad 111. Aconductive bonding member may be provided to each of the first pad 111and the anode of the light emitting diode 120. As the conductive bondingmember, conductive pastes formed of a conductive material, for example,silver (Ag) pastes, may be used. Accordingly, the first pad 111 and theanode 121 of the light emitting diode 120 are electrically connected toeach other therethrough.

The second pad 130 may be disposed in the luminous region and along aregion adjacent to the luminous region, specifically along thecircumference of the luminous region, as shown in FIG. 4 . The secondpad 130 is disposed at a location separated from the light emittingdiode 120.

The second pad 130 may be disposed outside the plurality of first pads111. The second pad 130 may be provided in plural. For example, foursecond pads 130 are disposed outside the plurality of first pads 111 tosurround the first pads 111.

The second pads 130 may be connected to the cathodes 129 of the lightemitting diodes 120 by wire bonding. In other words, an upper surface ofeach of the second pads 130 is connected to the cathode of the lightemitting diode 120 through a wire W, as shown in FIG. 4 . Here, althoughthe second pads 130 are connected to the cathodes of the light emittingdiodes 120 through two wires W, it should be understood that thisstructure is provided for convenience of description and a single wireor a different number of wires W may be used.

In embodiments of the present disclosure, the number of light emittingdiodes 120 and the number of first and second pads 111, 130 are notlimited thereto and may be determined in various ways.

The non-luminous region is provided with the terminal unit electricallyconnected to the pad portion. The terminal unit is disposed in a regionon the substrate 110 in which the reflector 180 and the window 190 arenot disposed.

The terminal unit is provided to one side of the substrate 110 tofacilitate connection to an external power source and includes a firstterminal 141 and a second terminal 143, as shown in FIG. 3 . However, itshould be understood that the location of the terminal unit is notlimited thereto and may be changed.

The first terminal 141 is electrically connected to the first pad 111.In the embodiment, the first terminal 141 may be integrally formed withthe substrate 110. When the substrate 110 is formed of a metal, thefirst pad 111 is electrically connected to the first terminal 141. Thesecond terminal 143 may be placed near the first terminal 141 and may beelectrically connected to the second pad 130. The second terminal 143may be electrically connected to the second pad 130 through a conductivewire on the substrate 110, as in a wire formed on a printed circuitboard.

Each of the first terminal 141 and the second terminal 143 may beprovided with a separate compression terminal so as to be electricallyconnected to an external power source connector.

In this embodiment, the first terminal 141 and the second terminal 143are formed of a conductive material. For example, the first and secondterminals 141, 143 may be formed of a metal. The metal may includecopper, iron, nickel, chromium, aluminum, silver, gold, titanium,palladium, and alloys thereof. In addition, each of the first and secondterminals 141, 143 may be a single layer film or a multilayer film. Forexample, the first and second terminals 141 and 143 may be formed ofNi/Au, Ni/Ag and Ni/Pd/Au.

The antistatic element 160 may be further provided to the terminal unit.The antistatic element 160 may be electrically connected to the firstand second terminals 141, 143 and may be realized by a Zener diode or atransient voltage suppressor (TVS). The antistatic element 160 preventsdamage to the light emitting apparatus due to discharge or surge ofstatic electricity.

In addition to the antistatic element 160, the temperature measurementdevice 170 may be further disposed on the substrate 110. The temperaturemeasurement device 170 may serve to measure the temperature of the lightemitting apparatus due to operation of the light emitting diodes 120.According to one embodiment, the temperature measurement device 170 maymeasure resistance to determine the temperature of the light emittingapparatus.

In addition, a terminal may be formed on the substrate 110 to beconnected to an element connector DC for supplying power to theantistatic element 160 and/or the temperature measurement device 170, asshown in FIG. 3 .

Next, the light emitting apparatus according to the embodiment of thepresent disclosure will be described in detail with reference to FIGS.1-4 .

The light emitting apparatus includes the substrate 110, the first pads111, the second pads 130, the light emitting diodes 120, the reflector180, and the window 190, which are mounted on the substrate 110.

The substrate 110 may have a plate shape and a substantially flat uppersurface. Here, in the luminous region on which the light emitting diodes120 are mounted, the first pads 111 may be integrally formed with thesubstrate 110. For example, the first pads 111 may be realized byprotrusions protruding from the upper surface of the substrate 110. Whenthe substrate 110 is used as the first pads 111, an external powersource may be electrically connected to the substrate 110 in order tosupply electric power to the first pads 111. In addition, with thestructure where the first pads 111 are integrally formed with thesubstrate 110, heat generated from the light emitting diodes 120 mountedon the first pads 111 can be directly transferred to the substrate 110through the first pads 111, thereby enabling rapid dissipation of heat.Further, although not shown in the drawings, the first terminal 141, thefirst terminal 141 (161) for the antistatic element 160, and thetemperature measurement device 170 may also be realized by protrusionsprotruding from the upper surface of the substrate 110 in the luminousregion thereof.

A first insulating layer 103 is formed on the substrate 110. The firstinsulating layer 103 serves to insulate the first pads 111 from thesecond pads 130. The first insulating layer 103 covers at least part ofthe upper surface of the substrate 110. In this embodiment, as shown inFIG. 4 , the first insulating layer 103 is formed in most regions of thesubstrate 110 excluding regions of the substrate 110 in which theprotrusions are formed.

In some forms, the first insulating layer 103 may be formed of variousinsulating materials having adhesive strength, for example, a polymerresin. The material of the first insulating layer 103 is notparticularly limited.

The second pads 130 are disposed on the first insulating layer 103 andare disposed adjacent to the first pads 111 so as to be spaced aparttherefrom. As shown in the drawings, the second pads 130 may be disposedon opposite sides of the luminous region, respectively, and may beelectrically connected to the light emitting diodes 120 by wires W.Here, the second pads 130 may have the same height as the first pads111. The second pads 130 are electrically insulated from the first pads111 by the first insulating layer 103.

In this embodiment, the first pads 111 and the second pads 130 areformed of a conductive material. For example, the first pads 111 and thesecond pads 130 may be formed of a metal, which may include copper,iron, nickel, chromium, aluminum, silver, gold, titanium, palladium, andalloys thereof. In one embodiment, one of the first pad 111 and thesecond pad 130, particularly, the second pad 130, may be a single layerpad or a multilayer pad. For example, the first pads 111 and the secondpads 130 may be formed of Ni/Au, Ni/Ag and Ni/Pd/Au.

A second insulating layer 105 may be formed in a region of the substrate110, on which the second pad 130 is disposed.

The second insulating layer 105 may be formed of various insulatingmaterials, for example, a photosensitive resist (PSR). However, itshould be understood that the material of the second insulating layer105 is not limited thereto.

The second insulating layer 105 covers most of the upper surface of thesubstrate 110 except for some regions of the first pads 111 and thesecond pads 130 adjacent to the luminous region. The light emittingdiodes 120 are disposed on the first pads 111 to which the secondinsulating layer 105 is not provided, and the wire W is connected to thesecond pads 130 to which the second insulating layer 105 is notprovided.

The second insulating layer 105 is not formed on at least part of thefirst and second terminals 141, 143 and the substrate holes. Inaddition, the second insulating layer 105 is not formed on the first andsecond terminals 141, 143 for the antistatic element 160, on which theantistatic element 160 is mounted, and is not formed on the terminal forthe temperature measurement device 170. Upper surfaces of theprotrusions of the substrate 110 or upper surfaces of the second pads130 may be exposed on a portion of the substrate 110 to which the secondinsulating layer 105 is not provided, as shown in FIG. 4 .

The reflector 180 is disposed on the second insulating layer 105. Thereflector 180 is disposed on the substrate 110 and may be bonded to thesubstrate 110 by the bonding layer 107. The bonding layer 107 isdisposed between the reflector 180 and the substrate 110 and may beapplied to regions of the substrate 110 excluding the substrate holes.

As such, the reflector 180 may be coupled to the substrate 110 by thebonding layer 107 and may be coupled again thereto by fastening members,as shown in FIGS. 1-4 . Here, when the reflector 180 is normally placedon the substrate 110, the fastening hole 151 of the reflector 180extends to the corresponding substrate hole of the substrate 110 to forma single hole and a fastening member, such as a screw 153, recouples thereflector 180 to the substrate 110 through the fastening hole 151 andthe substrate hole. As such, by recoupling the reflector 180 to thesubstrate 110 using the fastening member, it is possible to prevent thereflector 180 from being separated from the substrate 110 even whenadhesive strength of the bonding layer 107 is reduced due to heatgenerated from the light emitting diodes 120. Here, the bonding layer107 may contain a material capable of transferring heat from thesubstrate 110 to the reflector 180.

The window 190 is disposed on the stepped portion 181 of the reflector180 and may also be disposed on the bonding layer, although not shown inthe drawings. The window 190 is disposed above the light emitting diodes120 and overlaps the light emitting diodes 120 in plan view. The window190 may have various shapes and may change the traveling path of lightemitted from the light emitting diodes 120. In one embodiment, thewindow 190 may narrow the beam angle of light emitted from the lightemitting diodes 120 to a predetermined angle or less.

FIG. 6A is a perspective view of the window in the light emittingapparatus according to the embodiment of the present disclosure, andFIG. 6B and FIG. 6C are cross-sectional views of the window taken alongline II-II′ of FIG. 6A.

Referring to FIG. 6A to FIG. 6C, a window 190 according to oneembodiment of the present disclosure includes a base 191 having a plateshape and a lens portion 193 protruding from one surface of the base191.

The base 191 may include a plate having a shape corresponding to theopening of the reflector 180 (see FIG. 1 through FIG. 4 ), for example,a rectangular shape. The base 191 has a size corresponding to the sizeof the opening so as to be seated on the stepped portion in the openingof the reflector 180. However, it should be understood that the shape orsize of the base 191 is not limited thereto and may be changed accordingto the shape of the opening and/or the stepped portion.

The lens portion 193 is formed on one surface of the base 191 andprotrudes from the one surface of the base 191. Here, the lens portion193 may be convex in a light traveling direction. The lens portion 193serves to condense light emitted from light emitting diodes 120 and hasa convex lens shape.

In one embodiment, the base 191 may be integrally formed with the lensportion 193, but is not limited thereto. Alternatively, the base 191 andthe lens portion 193 may be separately formed and coupled to each other.

The lens portion 193 may include a bottom contacting the base 191 and acurved portion 193 corresponding to a portion protruding from the base191, and has a substantially hemispherical shape. The lens portion 193may have a circular shape in plan view. That is, the bottom of the lensportion has a circular shape. However, it should be understood that thebottom of the lens portion is not limited thereto and may have anelliptical shape or other shapes.

In this embodiment, although the lens portion 193 has a substantiallyhemispherical shape, the lens portion 193 does not have an accuratehemispherical shape and has a smaller height than the hemisphericalshape. In other words, a cross-section of the lens portion 193 takenalong the center of the circular shape is not a semi-circularcross-section. The lens portion 193 has a smaller height than a diameterD of a circle constituting the bottom of the base. In particular, theheight of the lens portion 193 may be 70% or less of the diameter D ofthe bottom.

Here, the height H of the lens portion 193 means the shortest distancefrom the bottom to the vertex of the lens portion 193, that is, adistance from the bottom to the vertex of the lens portion 193 in adirection perpendicular to the base 191. When the bottom has a circularshape, the height H of the lens portion 193 refers to a distance from anupper surface of the base 191 to a point the lens portion 193corresponding to the center of a circular shape thereof.

In one embodiment, in a cross-section of the lens portion 193perpendicular to the upper surface of the base 191 and taken along thecenter of the circular shape on the base 191, the lens portion 193 mayhave different gradient variations depending upon an angle from theupper surface of the base with reference to the center of the circularshape. In particular, the lens portion 193 is configured to have agradient variation that gradually increases and then decreases.

Accordingly, in the window 190 according to the embodiment, when thelens portion 193 is divided into a plurality of regions according to anangle from the upper surface of the base 191 with reference to thecenter of the circular shape, a gradient variation in each region isdifferent from that of another region adjacent thereto. For example,assuming that the lens portion 193 sequentially has first to m^(th)regions (m being an integer of 3 or more) according to the angle fromthe upper surface of the base with reference to the center of thecircular shape, a gradient variation in an n^(th) region (1<n<m) may begreater than a gradient variation in an (n−1)^(th) region and a gradientvariation in an (n+1)^(th) region.

In FIG. 6B, for convenience of description, the lens portion 193 isdivided into 6 sectors according to an angle from the upper surface ofthe base 191 with reference to the center of the circular shape andangles changed between lines connecting both sides of an arc of eachsector are denoted by θ1, θ2, θ3, θ4, and θ5, respectively. Referring toFIG. 6B, the variations in angle, that is, the gradient variations, mayhave different values in regions adjacent to one another and may have ashape that gradually increases and then decreases again. In particular,the gradient variations are gradually changed such that the variation ofthe angle in the fifth region is the largest and the variation of theangle in the sixth region tends to decrease again.

In addition, the curved portion has different radii of curvaturedepending on the location thereof. For example, in a cross-section ofthe lens portion 193 taken across the center of the lens portion 193,the curved portion may have different radii of curvature depending onthe height of the lens portion 193 from the bottom thereof.

According to one embodiment, in the cross-section taken across thecenter of the lens portion 193, the radius of curvature of a curveconstituting the lens portion 193 does not monotonously increase ordecrease from the upper surface of the base 191 to the vertex of thelens portion 193. According to the embodiment, in the cross-sectiontaken across the center of the lens portion 193, the radius of curvatureof the curve constituting the lens portion 193 may gradually increaseand then decrease from the upper surface of the base 191 to the vertexof the lens portion 193. Accordingly, in the cross-section taken acrossthe center of the lens portion 193, a portion having the smallest radiusof curvature may be placed between the lowermost portion of the lensportion 193 and the uppermost portion of the lens portion 193 (that is,the vertex thereof).

By way of example, assuming that radii of curvature of three points P1,P2, P3 arranged in sequence on the cross-section taken across the centerof the lens portion 193 is first to third radii of curvature, a pointhaving the smallest radius of curvature may be placed between the firstpoint and the third point. Assuming that the point having the smallestradius of curvature is the second point P2 on the cross-section takenacross the center of the lens portion 193, the second radius ofcurvature is smaller than the first and third radii of curvature. Here,the light emitting diodes are disposed in a region on the surface of thesubstrate corresponding to a region between the points having thesmallest radius of curvature at both sides (indicated by D′ in thedrawing) on the cross-section taken across the center of the lensportion 193, that is, between the second points P2 at both sides. In thelens portion 193, since the radius of curvature gradually increases fromthe second point P2 having the smallest radius of curvature to the thirdpoint P3, condensation of light emitted from the light emitting diodesand traveling upwards from the bottom is easily achieved.

In one embodiment, when the light emitting diode is provided in plural,all of the light emitting diodes may be disposed in the region D′between the points having the smallest radius of curvature at both sideson the cross-section taken across the center of the lens portion 193.Accordingly, the light emitting diodes disposed in the outermost regionsmay also be disposed between the points D′ having the smallest radius ofcurvature at both sides on the cross-section taken across the center ofthe lens portion 193.

For example, when the light emitting diodes are arranged in a p×qmatrix, all of the light emitting diodes including light emitting diodeslocated in the outermost regions of the p×q matrix (that is, 1 row 1column, p row 1 column, 1 row q column, p row p column) may be disposedbetween the points D′ having the smallest radius of curvature at bothsides on the cross-section taken across the center of the lens portion193.

When the light emitting diode is provided in plural, the quantity oflight is different between the top of each of the light emitting diodes120 and a gap between adjacent light emitting diodes 120. As a result,depending on arrangement of the light emitting diodes 120, portionshaving larger and smaller quantities of light intensity than adjacentportions may appear alternately, whereby peaks and valleys may appearclearly in a light profile. In this case, it is difficult to achieveuniform irradiation with light due to difference in quantity of lightdepending on the location. However, when light is condensed through thewindow 190, the valley is significantly reduced in the light profile andthe difference in quantity of light according to the location within abeam angle of 90 degrees is significantly reduced. Accordingly, uniformlight may be implemented as a whole without a sudden change in quantityof light.

In the following description, light profiles of light emittingapparatuses including a conventional window and the window having theabove structure will be compared.

FIG. 7A and FIG. 7B are a view of a conventional window and a lightprofile of a conventional light emitting apparatus including the same,and FIG. 8A and FIG. 8B are a view of a window according to oneembodiment of the present disclosure and a light profile of a lightemitting apparatus including the same, respectively. Here, theconventional light emitting apparatus and the light emitting apparatusaccording to the embodiment are manufactured under the same conditionsexcept for the window. Nine (9) light emitting diodes were arranged in a3×3 matrix and a distance between adjacent light emitting diodes was 200micrometers. The window shown in FIG. 7A and FIG. 7B had adiameter-to-height ratio of 76% and the window shown in FIG. 8A and FIG.8B had a diameter-to-height ratio of 55%.

First, referring to FIG. 7A and FIG. 7B, when the lens portion isdivided into 6 sectors according to an angle from the upper surface ofthe base with reference to the center of the circular shape and gradientvariations between lines connecting both sides of an arc of each sectorare denoted by first to fifth variations, respectively, the first tofifth variations have different values in adjacent regions and graduallyincrease.

In a light profile of the light emitting apparatus employing such awindow, although the beam angle is within 90 degrees, there is a largedifference in quantity of light according to the angle. As a result, thepeaks and the valleys are clearly shown in the light profile and,although there are differences depending on the angle, there is asection in which the quantity of light corresponding to the valley isonly about 50% of the quantity of light at the peak. These peaks andvalleys are caused by the distance between adjacent light emittingdiodes and, in this case, it is difficult to achieve uniform irradiationwith light due to difference in quantity of light depending on thelocation, as shown in FIG. 7B.

Next, referring to FIG. 8A and FIG. 8B, when the lens portion is dividedinto 6 sectors according to an angle from the upper surface of the basewith reference to the center of the circular shape and gradientvariations between lines connecting both sides of an arc of each sectorare denoted by first to fifth variations, respectively, the first tofifth variations have different values in adjacent regions and have ashape in which the variations gradually increase and then decrease.

In a light profile of the light emitting apparatus employing such awindow, the beam angle is within 90 degrees and the quantity of lightaccording to the angle also shows a constant tendency and a uniformvalue as a whole. That is, in the light profile, there is only a largepeak as a whole and a valley is not clearly shown. Even when there is apeak, the difference between the valley and the peak is less than 10%,as shown in FIG. 8B.

As a result, it can be seen that, even with the same light emittingdiodes as the light emitting apparatus shown in FIG. 7A and FIG. 7B, thelight emitting apparatus shown in FIG. 8A and FIG. 8B exhibitsimprovement in uniformity and concentration of light and uniformirradiation with light is facilitated due to difference in quantity oflight depending on the location.

FIG. 9A to FIG. 9C are simulation profiles of light emitted from aconventional light emitting apparatus including a window and FIG. 10A toFIG. 10C are simulation profiles of light emitted from a light emittingapparatus including a window according to one embodiment of the presentdisclosure. Here, the conventional light emitting apparatus and thelight emitting apparatus according to the embodiment are manufacturedunder the same conditions except for the window. The conventional lightemitting apparatus employed the window shown in FIG. 7A and the lightemitting apparatus according to the embodiment employed the window shownin FIG. 8A.

In FIG. 9A and FIG. 10A, nine (9) light emitting diodes were arranged ina 3×3 matrix and a distance between adjacent light emitting diodes was200 micrometers. In FIG. 9B and FIG. 10B, nine (9) light emitting diodeswere arranged in a 3×3 matrix and had a larger area than the lightemitting diodes shown in FIG. 9A and FIG. 10A. Here, a distance betweenadjacent light emitting diodes was 200 micrometers. In FIG. 9C and FIG.10C, sixteen (16) light emitting diodes were arranged in a 4×4 matrixand had a larger area than the light emitting diodes shown in FIG. 9Aand FIG. 10A. Here, a distance between adjacent light emitting diodeswas 200 micrometers.

Referring to FIG. 9A to FIG. 9C, although the beam angle is within 90degrees, there is a large difference in quantity of light according tothe angle. As a result, the peaks and the valleys are clearly shown inthe light profile. It is difficult to achieve uniform irradiation withlight due to difference in quantity of light depending on the location.

Referring to FIG. 10A through FIG. 10C, the beam angle is within 90degrees and the quantity of light according to the angle also shows aconstant tendency and a uniform value as a whole. That is, in the lightprofile, there is only a large peak as a whole and a valley is notclearly shown.

As such, it can be seen that the light emitting apparatus according tothe teachings of the present disclosure achieves improvement inuniformity and concentration of light.

FIG. 11A to FIG. 11C are light profiles of light emitting apparatuseseach including a window according to the teachings of the presentdisclosure, in which the window has a similar shape to the window shownin FIG. 8A and a different height from the window shown in FIG. 8A.Here, the light emitting apparatuses according to the embodiments weremanufactured under the same conditions as ones of FIG. 8A except for thewindow. FIG. 11A shows a window includes a base having a diameter of 10mm and a height of 4.5 mm, FIG. 11B shows a window includes a basehaving a diameter of 10 mm and a height of 5.5 mm, and FIG. 11C shows awindow includes a base having a diameter of 10 mm and a height of 6.5mm.

Referring to FIG. 11A to FIG. 11C, for all of the light emittingapparatuses, the beam angle is within 90 degrees and the quantity oflight according to the angle also shows a constant tendency and auniform value as a whole. That is, in the light profile, there is only alarge peak as a whole and a valley is not clearly shown. Here, it can beseen that even an unclear portion that is determined to be a valley hadlittle difference in intensity from all peaks.

As described above, in the light profile, the valley is significantlyreduced and the difference in quantity of light according to thelocation within a beam angle of 90 degrees is also significantlyreduced. Accordingly, it is possible to realize uniform light withoutrapid variation in intensity of light. As a result, the light emittingapparatus according to the embodiment of the present disclosure canprovide light having high directionality while minimizing deviation inintensity of light in a predetermined region.

The light emitting apparatus according to one or more embodiments of thepresent disclosure may be realized in various sizes and shapes and maybe provided singularly or in plural to other devices. FIG. 12 is aperspective view of a light emitting apparatus according to oneembodiment of the present disclosure. The following description willfocus on different features of the embodiment from the above embodimentsin order to avoid repetition of description and components havingsubstantially the same functions are denoted by the same or likereference numerals.

Referring to FIG. 12 , the light emitting apparatus according to theembodiment has a generally similar shape to the light emitting apparatusshown in FIG. 1 except for a substrate 110, reflectors, and the like.The substrate 110 may have a rectangular shape having long sides andshort sides and the reflectors may be disposed at opposite sides of thelight emitting diode to be spaced apart from each other. A firstterminal 141 and a second terminal 143 are provided to opposite ends ofthe substrate 110 at which the reflector is not formed.

As such, the light emitting apparatuses having various shapes may bearranged in various ways to achieve efficient illumination of a targetwith light.

The light emitting apparatus according to the embodiments may beemployed in various devices. For example, the light emitting apparatusaccording to the embodiments may be used for a light radiator. The lightradiator emits light to various materials for various purposes. In oneembodiment, the light radiator may be used to cure polymeric materials.The light radiator may include at least one light emitting apparatusdescribed above.

Although some embodiments have been described herein, it should beunderstood by those skilled in the art that these embodiments are givenby way of example only, and that various modifications, variations, andalterations can be made without departing from the spirit and scope ofthe present disclosure.

Therefore, it should be understood that the scope of the presentdisclosure should be defined by the appended claims and equivalentsthereto.

What is claimed is:
 1. A light emitting device comprising: a substratehaving a luminous region and a non-luminous region; a plurality of lightemitting structures disposed on the luminous region of the substrate andconfigured to emit light with a first range of a beam angle, each lightemitting structure having an anode and a cathode; a window having a domeshape and disposed to cover the luminous region, the window configuredto control a traveling path of light emitted from the plurality of lightemitting structures by condensing the light emitted from the pluralityof light emitting structures to have a second range of the beam anglethat is not greater than the first range of the beam angle; a reflectorconfigured to support the window and reflect the light emitted from theplurality of light emitting structures, wherein the reflector has anopening that exposes the plurality of light emitting structures mountedon the substrate; and an adhesive layer disposed between the window andthe reflector; first pads disposed in the luminous region to correspondto the plurality of light emitting structures, the first padselectrically coupled to anodes of the plurality of light emittingstructures, respectively; and a second pad disposed along acircumference of the luminous region and separately from the pluralityof light emitting structures, the second pad electrically coupled tocathodes of the plurality of light emitting structures, wherein adistance between two adjacent light emitting structures of the pluralityof light emitting structures is 500 micrometers or less.
 2. The lightemitting device of claim 1, wherein the non-luminous region is providedwith conductive patterns electrically connected to the plurality oflight emitting structures.
 3. The light emitting device of claim 1,wherein the first range of the beam angle is 90 degrees or more and thesecond range of the beam angle is 90 degrees or less.
 4. The lightemitting device of claim 1, wherein, in a light profile of light emittedfrom the light emitting device, a difference between a valley value anda peak value is 10% or less.
 5. The light emitting device of claim 1,wherein the opening defines the luminous region.
 6. The light emittingdevice of claim 1, wherein a height of the window is 70% or less of alower diameter thereof.
 7. The light emitting device of claim 1, whereinthe distance between the two adjacent light emitting structures of theplurality of light emitting structures is 200 micrometers.
 8. The lightemitting device of claim 1, wherein each of the first pad is disposedbetween the substrate and each of the light emitting structures; and theplurality of light emitting structures are connected to the second padby electrical bonding.
 9. The light emitting device of claim 1, whereinthe light emitting structures emit UV light.
 10. A light emitting devicecomprising: a substrate having a first region and a second region; aplurality of light emitting structures disposed on the first region ofthe substrate, each light emitting structure having an anode and acathode; a window having a dome shape and disposed to cover the firstregion, the window configured to control a traveling path of lightemitted from the plurality of light emitting structures; and a reflectorconfigured to support the window and reflect the light emitted from theplurality of light emitting structures, wherein the reflector has anopening that exposes the plurality of light emitting structures mountedon the substrate; first pads disposed in the first region to correspondto the plurality of light emitting structures, the first padselectrically coupled to anodes of the plurality of light emittingstructures, respectively; and a second pad disposed along acircumference of the first region and separately from the plurality oflight emitting structures, the second pad electrically coupled tocathodes of the plurality of light emitting structures, wherein, in aprofile of light emitted from the light emitting device, a differencebetween a valley value and a peak value is 10% or less.
 11. The lightemitting device of claim 10, wherein a distance between two adjacentlight emitting structures is 500 micrometers or less.
 12. The lightemitting device of claim 10, wherein the second region is provided withconductive patterns electrically connected to the light emittingstructures.
 13. The light emitting device of claim 10, wherein theplurality of light emitting structures emit light, via the dome shape ofthe window, at a beam angle of 90 degrees of more.
 14. The lightemitting device of claim 10, wherein the opening defines the firstregion.
 15. A light emitting device comprising: a substrate having aluminous region and a non-luminous region; a light emitting unitdisposed on the luminous region of the substrate and including aplurality of light emitting structures configured to emit light, eachlight emitting structure having an anode and a cathode; a windowdisposed to cover the luminous region, the window configured to controla traveling path of light emitted from the light emitting unit; areflector configured to support the window and reflect the light emittedfrom the light emitting unit, wherein the reflector has an opening thatexposes the light emitting unit mounted on the substrate; and anadhesive layer disposed between the substrate and the reflector; firstpads disposed to correspond to the plurality of light emittingstructures and electrically coupled to anodes of the plurality of lightemitting structures, respectively; and a second pad disposed outside thefirst pads and the plurality of light emitting structures, the secondpad electrically coupled to cathodes of the plurality of light emittingstructures, wherein, in a light profile of light emitted from the lightemitting device, a difference between a valley value and a peak value is10% or less.
 16. The light emitting device of claim 15, wherein thenon-luminous region is provided with conductive patterns electricallyconnected to the light emitting unit.
 17. The light emitting device ofclaim 15, further comprising a phosphor portion disposed in the window.18. The light emitting device of claim 15, wherein the reflector has astepped portion on a top surface thereof.
 19. The light emitting deviceof claim 15, wherein an inner wall of the opening has an inclinedportion.